Controlling means for electric motors



L. KEBLER.

CONTROLLING MEANS FOR ELECTRIC MOTORS.

APPLICATION FILED [13,19]?- Patented Jan. 20,1920.

ELECTRIC CO., A CORPORATION OF NEW YORK.

CONTROLLING MEANS FOR ELECTRIC MOTORS.

Application filed February 3, 1917.

To all whom it may concern:

Be it known that I, LEONARD Kristen, a citizen of the United States,residing at Bronxville, in the county of Westchester and State of NewYork, have invented certain new and useful Improvements in ControllingMeans for Electric Motors,of whlch the following is a specification.

The principal object of my invention is to provide a new and improvedstarting panel for electric motors. Another object of my invention is toprovide a circuit breaker and a starting rheostat combined in such a waythat the movable member of the rheostat must be at a proper positionbefore a normal enduring closure of the circuit breaker can be effected.Another object of mymvention is to provide a circuit breaker with meansfor holding it in closed position in combination with a startingrheostat and mechanism that will prevent the holding means from beingefiective at starting, unless the rheostat is properly adjusted. Anotherob]ect of my invention is to provide a clrcult breaker to be operated byeither overload or no voltage in combination with a starting rheostatand mechanism that will require a particular adjustment of this rheostatto insure proper closing oi the circuit breaker at starting. Anotherobject of my invention is to provide a rheostat grid with a new andimproved protective coating. All these objects and others will be madeapparent in the following specification and claims taken with theaccompanying drawing.

In this drawing I have shown in a diagrammatic way one specificembodiment of my invention.

The two line conductors 9 and 9 to the motor comprise the contacts 10and 10 adapted to be closed respectively by the bridging pieces 12 and12 of the circuit breaker. Each such bridging piece as 12 is carried bya pivoted arm 11 provided with a handle 14 and adapted to be retractedby a s ring 15 unless held in the closed position by the latch 13.Normally the latch 13 is held in efiective latching position by thespring 16.

Continuing w is an overload e01 18 which carr1es when raised to trip Themotor field win connected directly across th the line conductor 9 there1 17 with an associated core the cross arm 19 adapted the latches 13 and13.

ding 20 is in shunt the line wires 9 Specification of Letters Patent.

Patented Jan. 20, 1920.

Serial No. 148,502.

and 9. The armature starting resistance is in a series of sections 21connected to contacts 37 as shown at the lower part of the diagram. Aslide 22 is provided with a handle 23 and is mounted on appropriateguides so that it can be moved up and down manually and thus connectacross between any pair of contacts 37 and include more or less of theresistance 21 in series in the circuit. Thus the variable resistance 21and the armature are connected in series by the conductor 24 across theline 99 and in shunt with the field 20.

Another conductor 28 is connected across the line wires 99 and comprisesthe no voltage coil 26 and the series resistance 27. Also in theconductor 28 there is a normally closed push button switch indicated at29. The pivoted arm 30 carries a keeper 3i adapted to be held by the novoltage coil 26 when the latter is suiiiciently energized. The spring 31acts in opposition to the restraint of the coil 26 on the keeper 34. Anarm 33 is connected by the link 32 to the arm 30, and is pivoted so thatits free end lies in the path of the slide 22, when the latter is at theresistance-all-in position.

When the arm 30 is released by the underload coil 26 and raised by thespring 31, it strikes the plunger 35 which pushes against the stem 36hanging down from the core 18 and thus raises the cross arm 19 to tripthe latches 13 and 13.

The resistance 21 is made up of a plurality of iron grids which aresupported behind the panel on which the apparatus indicated in thedrawing is mounted. These iron grids are coated with enamel or withcomparatively infusible material. The coating may be an infusiblematerial of good heat conductively or may be of the general typedescribed in the Leonard Patents 863,293 of August 13, 1907, and 576,202of February 2, 1897, but I mention these patents merely by way ofexample. This coat- 10 ing is infusible at the ordinary temperatures ofthe muflle furnace, but at the fusing temperature of iron it may becomemore or less viscous, still retaining a certaln amount of mechanicalstrength. Accord ngly, 1f a 105 temperature at which the resistance gr dwill burn out is attained, the COM W111 either be quite infusible or maybecome plastic and tend to cement the particles 0f 1I0I together. Ineither case it w1ll prevent 110 ing independently closable arms, lockingmechanism therefor, movable means for unlocking said mechanism, arheostat, and means controlled by the movable element of said rheostatfor engaging said movable means and shifting it to an ineffectiveposition.

17. In combination, a circuit breaker having independently closablearms, mechanism for restraining said breaker in closed position, movablemeans for causing said restraining mechanism to be ineflective, arheostat, and means controlled by said rheostat for engaging saidmovable means and shifting it to an ineffective position.

18. In combination, a circuit breaker,

mechanism for restraining said breaker in closed position, movable meansfor causing said restraining mechanism to be inefl'ective, a rheostat, ano voltage Winding, and means controlled by said rheostat and said novolt age Winding for controlling said movable means.

19. In combination, a circuit breaker, a rheostat, correlated means toopen the circuit breaker, means to hold said circuit breaker closed, andmechanism operatively associated with the rheostat to render saidholding means ineffective unless the rheostat is in the initial positionof adjustment.

LEONARD KEBLER.

B. A. PLIMPTON.

INSULATOR SUPPORT.

APPLICATION man OCT. 31. 1917.

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